SCREW CONSTRUCTION OF DOUBLEESPINDLED EXTRUDER

摘要

PURPOSE:To accomplish even and tense kneading of the molding material by making the first screw tapered from one end to the other while the second one facing thereof tapered in the opposite way. CONSTITUTION:The first screw 3 and the second screw 5 are provided in the barrel 7 of a double spindled extruder. The screw spindle forming the valley of the first screw 3 is shaped in such a tapered from that the diameter thereof becomes smaller toward the tip thereof. The spindle 6 of the second screw is tapered toward the base end in a tapered shape opposite to the screw spindle 4. The two screws are so arranged to engage each other at the blades 9 and 10 while incompletely engaging when the pitches of the blades are large. The portions facing each other of the two screw spindles vary from each other in the diameter, which allows difference in the shearing speed at sections thereby enabling even shear kneading of the molding material along with a strong kneading.